Zircon U-Pb and Lu-Hf Isotopic Dating of Magmatic Rocks in the Wunugetushan Porphyry Copper-Molybdenum Deposit, Inner Mongolia
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摘要:
位于额尔古纳—呼伦断裂北西侧的乌努格吐山铜钼矿为一大型斑岩型铜钼矿床,矿区岩浆岩发育,为确定赋矿围岩和成矿母岩的侵位时代,探讨岩石成因,本文选择该矿床代表性的岩石样品,采用激光剥蚀多接收器电感耦合等离子体质谱法(LA-MC-ICP-MS)和激光剥蚀电感耦合等离子体质谱法(LA-ICP-MS),对岩浆岩的锆石U-Pb同位素和锆石Lu-Hf同位素进行了分析测定。研究表明:①研究区锆石稀土元素含量较高,重稀土强烈富集,具δEu负异常和δCe强正异常,稀土配分曲线具左倾特征;②不等粒二长花岗岩为赋矿围岩,锆石206Pb/238U加权平均年龄为200.96±0.88Ma(MSWD=3.0),岩体形成于早侏罗世,锆石Lu-Hf同位素特征表明岩浆源区为幔源物质和少量古老壳源物质的混合;③流纹质碎斑熔岩为成矿母岩,锆石206Pb/238U加权平均年龄为179.58±0.91Ma,形成于早侏罗世,锆石Lu-Hf同位素特征显示岩浆源区以幔源物质为主。研究结果揭示了从赋矿围岩到成矿母岩岩浆源区从壳源到幔源过渡的演化过程。
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关键词:
- 乌努格吐山铜钼矿 /
- LA-MC-ICP-MS /
- U-Pb同位素 /
- Lu-Hf同位素 /
- 岩石成因
Abstract:BACKGROUND The Wunugetushan copper-molybdenum deposit located in the northwest of the Erguna—Hulun fault is a large porphyry copper-molybdenum deposit. Magmatic rocks are widespread in the mining area.
OBJECTIVES In order to determine the emplacement age and tectonic setting of ore-hosting surrounding rock and ore-forming parent rock, and to discuss the petrogenesis and metallogenic dynamics.
METHODS Zircon U-Pb isotopes and zircon Lu-Hf isotopes of rocks were studied by laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) and laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS).
RESULTS (1) The zircons in the study area have a high content of REE with strong enrichment of HREE, δEu negative anomaly and δCe positive anomaly, and the REE distribution curves are left-inclined. (2) The anisomitic monzogranites are the ore-hosting rocks with a weighted average value of 200.96±0.88Ma, indicating that the rock mass was formed in early Jurassic. Zircon εHf(t) ranges from 0.1 to 5.8, single-stage Hf model ages (TDM) range from 643Ma to 882Ma, and two-stage Hf model ages (TDMC) range from 874Ma to 1235Ma. (3) The rhyolite porphyritic lavas are the ore-forming parent rocks with a weighted average value of 179.58±0.91Ma, indicating that the rocks formed in the Early Jurassic. Zircon εHf(t) ranges from 4.3 to 6.6, single-stage Hf model ages (TDM) range from 570Ma to 663Ma, and two-stage Hf model ages (TDMC) range from 802Ma to 952Ma.
CONCLUSIONS The zircon Lu-Hf isotopic characteristics of the anisomitic monzogranites indicate that the magma source is a mixture of mantle and a small amount of ancient crust. The magma source area of the rhyolite porphyritic lavas is dominated by mantle-derived materials. The transition evolution process from crust source to mantle source from host rock to metallogenic parent rock is revealed.
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Key words:
- Wunugetushan copper-molybdenum deposit /
- LA-MC-ICP-MS /
- U-Pb isotope /
- Lu-Hf isotope /
- petrogenesis
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图 4 稀土元素球粒陨石标准化配分型式(标准化数据据文献[38])
Figure 4.
图 5 不等粒二长花岗岩(WS05)锆石εHf(t)-t图(底图据文献[33])
Figure 5.
图 6 流纹质碎斑熔岩(WS02)锆石εHf(t)-t图(底图据文献[33])
Figure 6.
表 1 乌努格吐山岩体LA-MC-ICP-MS锆石U-Pb同位素分析结果
Table 1. LA-MC-ICP-MS zircon U-Pb isotopic analysis of the Wunugetushan rocks
样品名 元素含量(×10-6) Th/U 元素比值 年龄(Ma) Pb Th U 207Pb/206Pb 1σ 207Pb/235U 1σ 206Pb/238U 1σ 207Pb/206Pb 1σ 207Pb/235U 1σ 206Pb/238U 1σ WS02-1 6.63 99.33 106.28 0.93 0.054800689 0.002451556 0.21777954 0.009825907 0.028920427 0.0002901 466.71 99.99 200.06 8.19 183.79 1.82 WS02-2 21.18 360.70 357.46 1.01 0.052139056 0.001611966 0.19929428 0.005904684 0.027904962 0.0002414 300.06 70.36 184.53 5.00 177.42 1.51 WS02-3 9.71 127.12 187.62 0.68 0.053187486 0.001725981 0.20737534 0.006527215 0.028589719 0.0002581 344.50 74.07 191.35 5.49 181.72 1.62 WS02-4 23.29 335.12 435.58 0.77 0.0523526 0.001072423 0.2014723 0.00400281 0.028002268 0.0001724 301.91 46.29 186.37 3.38 178.03 1.08 WS02-5 8.61 90.78 183.57 0.49 0.055145614 0.001930204 0.21747196 0.007653397 0.028658462 0.0002537 416.72 77.77 199.80 6.38 182.15 1.59 WS02-6 20.64 291.00 376.00 0.77 0.054660963 0.001447771 0.2124608 0.005765492 0.028240433 0.0002631 398.20 59.25 195.62 4.83 179.53 1.65 WS02-8 8.18 135.96 138.07 0.98 0.054630817 0.002674734 0.20791517 0.009586314 0.028118499 0.0003531 398.20 109.25 191.80 8.06 178.76 2.21 WS02-9 26.43 382.25 491.17 0.78 0.052954664 0.000994737 0.20600679 0.003891296 0.028261949 0.000183 327.84 42.59 190.20 3.28 179.66 1.15 WS02-10 10.38 130.90 207.45 0.63 0.049377333 0.001784532 0.18873552 0.006546347 0.027953044 0.0002377 164.90 87.95 175.55 5.59 177.72 1.49 WS02-11 22.22 300.23 410.94 0.73 0.052497602 0.001023893 0.20769834 0.004161734 0.028732664 0.0001882 305.62 44.44 191.62 3.50 182.61 1.18 WS02-12 38.32 701.01 575.53 1.22 0.050521629 0.000821741 0.19443142 0.003348741 0.027897904 0.0001672 220.44 34.25 180.40 2.85 177.38 1.05 WS02-13 15.41 248.04 256.19 0.97 0.050553309 0.001345129 0.19415114 0.005059312 0.02803746 0.0002147 220.44 56.47 180.17 4.30 178.25 1.35 WS02-14 16.30 256.91 298.04 0.86 0.050617744 0.001296767 0.19604288 0.004959068 0.028254753 0.0002041 233.40 59.25 181.77 4.21 179.62 1.28 WS02-15 9.86 128.93 197.58 0.65 0.053200153 0.001778239 0.20301776 0.006439848 0.027963384 0.0002068 344.50 75.92 187.68 5.44 177.79 1.30 WS02-16 11.93 159.19 228.39 0.70 0.051343842 0.001688606 0.20303925 0.006728144 0.028755703 0.0002669 257.47 71.29 187.69 5.68 182.76 1.67 WS02-17 23.68 362.75 419.53 0.86 0.054711601 0.001166784 0.21235292 0.00470457 0.028205027 0.0002095 466.71 50.92 195.53 3.94 179.30 1.31 WS02-18 10.80 134.97 212.47 0.64 0.055085188 0.00186445 0.21549537 0.007139035 0.028663977 0.0002485 416.72 80.55 198.15 5.96 182.18 1.56 WS02-19 22.29 417.16 350.97 1.19 0.051618269 0.002041641 0.19860798 0.007722468 0.02798546 0.0002789 333.39 95.36 183.95 6.54 177.93 1.75 WS02-21 28.22 505.10 401.58 1.26 0.053629164 0.001209577 0.20969736 0.004457275 0.028636014 0.0002611 353.76 51.85 193.30 3.74 182.01 1.64 WS02-22 13.76 199.73 247.98 0.81 0.050498539 0.001704943 0.19981518 0.007007338 0.028780503 0.0003232 216.74 47.22 184.97 5.93 182.91 2.03 WS02-23 15.67 233.95 279.27 0.84 0.053609854 0.001945143 0.20426492 0.006872007 0.027979173 0.0002475 353.76 50.92 188.73 5.79 177.89 1.55 WS02-24 12.13 155.47 242.85 0.64 0.048139881 0.001435921 0.18517718 0.005419974 0.028059585 0.0002194 105.65 70.37 172.51 4.64 178.39 1.38 WS02-25 21.94 294.47 456.44 0.65 0.05015908 0.001703097 0.18973048 0.006066855 0.027568544 0.0002324 211.19 79.62 176.40 5.18 175.31 1.46 WS02-26 11.03 202.63 163.39 1.24 0.048642808 0.001868937 0.18622353 0.007027353 0.028034949 0.0002515 131.57 90.73 173.40 6.02 178.24 1.58 WS02-27 18.79 270.47 307.16 0.88 0.0592801 0.001671102 0.23539905 0.006493675 0.02893611 0.0002062 575.96 58.32 214.65 5.34 183.89 1.29 WS02-28 15.65 205.15 290.46 0.71 0.050701322 0.001279128 0.20087159 0.005146519 0.028781368 0.0002166 227.85 57.40 185.86 4.35 182.92 1.36 WS02-29 17.27 254.50 308.03 0.83 0.051600767 0.001357782 0.19851122 0.005220095 0.028089674 0.0002205 333.39 61.10 183.87 4.42 178.58 1.38 WS02-30 15.90 246.27 276.75 0.89 0.051720434 0.001294036 0.19826738 0.004938912 0.027877092 0.0001995 272.29 57.40 183.66 4.19 177.25 1.25 WS05-1 64.67 982.05 957.01 1.03 0.049821594 0.000679027 0.21445247 0.003309532 0.031186237 0.0002163 187.12 31.48 197.28 2.77 197.97 1.35 WS05-2 57.13 549.94 1168.26 0.47 0.051369046 0.00067504 0.22227668 0.003450735 0.031302054 0.0002225 257.47 29.63 203.80 2.87 198.69 1.39 WS05-3 47.18 434.72 1006.50 0.43 0.0506981 0.000730666 0.2174262 0.003523028 0.031061297 0.0002109 227.85 33.33 199.77 2.94 197.19 1.32 WS05-4 34.20 444.49 539.30 0.82 0.050076452 0.00089561 0.21978911 0.003838643 0.031905458 0.0002253 198.23 36.10 201.73 3.20 202.46 1.41 WS05-5 27.24 293.62 512.29 0.57 0.050704918 0.000898261 0.2223234 0.004083565 0.03180311 0.0002221 227.85 73.14 203.84 3.39 201.82 1.39 WS05-6 36.62 406.81 627.91 0.65 0.053227511 0.000811598 0.23413474 0.003583162 0.031928406 0.0001706 338.95 35.18 213.61 2.95 202.61 1.07 WS05-7 83.00 979.16 1509.58 0.65 0.050594466 0.00081154 0.21775243 0.003377792 0.031220547 0.0001736 233.40 37.03 200.04 2.82 198.18 1.09 WS05-8 32.42 390.91 580.70 0.67 0.050650678 0.000990998 0.21692246 0.004238077 0.031130835 0.000211 233.40 72.21 199.35 3.54 197.62 1.32 WS05-9 29.94 328.98 562.17 0.59 0.052125927 0.000943859 0.22710559 0.004118635 0.031673079 0.0002015 300.06 40.74 207.81 3.41 201.01 1.26 WS05-11 44.07 450.63 852.34 0.53 0.050493385 0.000603843 0.22279877 0.002627975 0.03205128 0.000192 216.74 32.40 204.24 2.18 203.37 1.20 WS05-12 11.55 105.13 237.06 0.44 0.051080959 0.001477309 0.22439572 0.00633483 0.032046799 0.0002526 242.66 66.66 205.56 5.25 203.35 1.58 WS05-14 42.65 589.47 697.76 0.84 0.05127644 0.001010592 0.22059852 0.004252904 0.031231933 0.000197 253.77 46.29 202.41 3.54 198.25 1.23 WS05-15 39.70 446.39 683.49 0.65 0.052426052 0.001056312 0.23066064 0.004658531 0.031933659 0.0002448 305.62 46.29 210.74 3.84 202.64 1.53 WS05-16 30.83 351.35 540.24 0.65 0.05575571 0.001034747 0.24554158 0.004129216 0.032092859 0.0002217 442.64 8.33 222.95 3.37 203.63 1.38 WS05-17 31.36 393.76 522.41 0.75 0.050483307 0.001147105 0.22167031 0.004880911 0.031926872 0.0002473 216.74 84.25 203.30 4.06 202.60 1.54 WS05-18 105.40 988.45 2090.24 0.47 0.055715982 0.000922293 0.2396987 0.003938731 0.031188268 0.0002232 442.64 4.63 218.17 3.23 197.98 1.40 WS05-19 41.50 594.60 650.78 0.91 0.052764976 0.000837416 0.22901688 0.00383827 0.031430675 0.0001724 320.43 35.18 209.39 3.17 199.50 1.08 WS05-20 32.81 439.05 545.05 0.81 0.050598044 0.001078644 0.22137187 0.004978527 0.031761313 0.0002199 233.40 80.54 203.05 4.14 201.56 1.37 WS05-21 35.38 283.00 748.80 0.38 0.053983443 0.000743583 0.23800768 0.003481432 0.031971686 0.0002069 368.57 63.88 216.79 2.86 202.88 1.29 WS05-22 28.57 328.62 500.85 0.66 0.050519726 0.001050105 0.22322756 0.004803931 0.032029526 0.0002293 220.44 48.14 204.59 3.99 203.24 1.43 WS05-23 42.59 608.47 643.73 0.95 0.049834093 0.000955096 0.22053286 0.004450034 0.032048558 0.0002182 187.12 44.44 202.35 3.70 203.36 1.36 WS05-24 8.17 60.44 177.56 0.34 0.052461445 0.001898692 0.22941335 0.00798765 0.032038934 0.0002929 305.62 83.33 209.71 6.60 203.30 1.83 WS05-25 24.90 213.14 529.34 0.40 0.053206234 0.000909342 0.23360332 0.004100044 0.031832937 0.0002027 344.50 38.89 213.17 3.37 202.01 1.27 WS05-26 30.48 333.52 561.03 0.59 0.050610366 0.00098056 0.22392893 0.004444282 0.032039082 0.0001895 233.40 78.69 205.17 3.69 203.30 1.18 WS05-27 42.92 359.80 939.57 0.38 0.053112655 0.000673233 0.23125454 0.003331502 0.031536009 0.0002358 344.50 27.78 211.23 2.75 200.15 1.47 WS05-28 24.77 245.33 487.82 0.50 0.05240212 0.001044812 0.23207116 0.004988243 0.032062634 0.0002458 301.91 44.44 211.91 4.11 203.44 1.54 WS05-29 88.23 961.68 1634.70 0.59 0.051403159 0.000521454 0.22632576 0.00277416 0.03194678 0.0002878 257.47 24.07 207.16 2.30 202.72 1.80 WS05-30 45.76 621.40 772.57 0.80 0.050900004 0.00083911 0.21961879 0.00358115 0.03129567 0.0001579 235.25 37.03 201.59 2.98 198.65 0.99 表 2 锆石稀土元素(×10-6)组成
Table 2. REE element (×10-6) compositions of the zircons
样品编号 La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Y ΣREE LREE HREE LREE/HREE δEu δCe WS05-1 0.009 30.818 0.109 2.207 5.808 1.336 37.462 14.819 189.182 78.302 365.255 82.336 775.232 155.907 2317.566 1738.78 40.29 1698.50 0.02 0.28 243.55 WS05-2 0.136 31.651 0.383 3.864 6.669 0.940 38.640 16.064 209.545 91.003 450.613 107.613 1082.980 229.910 2788.147 2270.01 43.64 2226.37 0.02 0.18 33.96 WS05-4 0.033 26.488 0.276 4.746 10.352 3.109 61.401 22.084 281.410 113.924 528.866 118.980 1130.763 227.279 3457.657 2529.71 45.00 2484.71 0.02 0.38 68.45 WS05-5 1.985 26.801 0.971 5.922 5.631 1.404 38.216 15.136 206.981 89.074 430.765 100.296 995.993 206.695 2738.920 2125.87 42.71 2083.16 0.02 0.29 4.73 WS05-6 7.588 48.479 4.041 22.978 9.309 1.237 35.817 12.572 166.430 71.866 347.266 81.181 817.296 167.611 2167.755 1793.67 93.63 1700.04 0.06 0.21 2.15 WS05-7 0.410 34.403 0.259 2.745 5.160 0.656 36.139 14.704 194.596 81.371 391.476 88.285 871.715 179.856 2485.255 1901.77 43.63 1858.14 0.02 0.15 25.90 WS05-8 0.071 26.437 0.180 3.754 6.534 1.671 45.710 17.406 241.011 104.037 496.093 114.322 1096.435 226.859 3098.375 2380.52 38.65 2341.87 0.02 0.30 57.53 WS05-9 0.634 19.833 0.405 4.501 6.978 1.302 43.246 15.843 207.008 86.747 414.299 94.644 940.131 191.090 2642.584 2026.66 33.65 1993.01 0.02 0.23 9.60 WS05-11 0.132 22.938 0.122 1.732 3.547 0.468 29.152 11.791 165.304 72.780 361.164 85.935 859.033 177.858 2241.112 1791.96 28.94 1763.02 0.02 0.14 44.37 WS05-12 0.004 8.790 0.057 1.131 3.136 0.640 19.128 7.017 97.977 41.175 206.170 48.490 497.626 104.694 1221.775 1036.03 13.76 1022.28 0.01 0.25 138.94 WS05-14 0.009 32.244 0.147 2.820 7.772 2.330 55.584 21.225 286.814 119.502 561.039 124.996 1187.688 245.743 3612.210 2647.91 45.32 2602.59 0.02 0.34 212.89 WS05-15 21.426 79.810 7.266 36.278 11.865 1.461 39.927 13.963 180.198 75.958 375.290 87.983 872.939 179.036 2355.693 1983.40 158.11 1825.29 0.09 0.21 1.57 WS05-16 0.293 20.491 0.259 4.083 8.775 1.680 49.344 17.701 216.112 87.518 406.557 90.786 878.944 176.341 2581.778 1958.88 35.58 1923.30 0.02 0.25 18.24 WS05-17 0.010 21.905 0.154 2.594 6.575 1.483 39.647 15.071 197.835 83.773 397.977 91.152 885.319 176.519 2547.626 1920.01 32.72 1887.29 0.02 0.28 133.88 WS05-18 0.236 45.705 0.646 6.351 8.428 0.844 47.397 19.589 265.616 113.368 545.382 128.379 1250.060 255.596 3519.237 2687.60 62.21 2625.39 0.02 0.13 28.68 WS05-19 0.106 31.726 0.695 12.497 23.102 5.938 113.735 37.357 433.393 165.370 720.022 158.983 1491.171 295.277 4901.935 3489.37 74.06 3415.31 0.02 0.35 28.69 WS05-20 0.018 21.968 0.154 2.858 6.418 1.727 45.681 17.085 223.461 92.612 432.575 100.645 974.587 198.240 2787.431 2118.03 33.14 2084.89 0.02 0.31 103.06 WS05-21 0.004 21.146 0.046 1.445 3.019 0.626 24.090 10.259 142.687 63.075 325.911 77.391 790.708 167.260 1970.759 1627.67 26.29 1601.38 0.02 0.22 407.07 WS05-22 0.009 21.816 0.142 3.198 6.343 1.554 41.438 15.424 207.699 87.686 414.011 96.134 937.960 194.215 2622.130 2027.63 33.06 1994.57 0.02 0.29 151.73 WS05-23 0.003 22.911 0.098 1.891 3.940 1.176 29.171 11.371 149.383 61.629 293.179 65.118 632.896 128.904 1849.730 1401.67 30.02 1371.65 0.02 0.34 316.29 WS05-25 0.002 16.515 0.045 1.028 3.357 0.484 23.728 10.029 137.925 61.334 312.802 75.410 763.433 161.320 1887.306 1567.41 21.43 1545.98 0.01 0.17 393.39 WS05-26 1.008 24.326 0.398 2.601 4.114 0.720 25.298 9.861 133.470 56.062 278.105 65.256 647.789 133.518 1756.502 1382.53 33.17 1349.36 0.02 0.22 9.41 WS05-27 0.092 25.471 0.132 1.488 3.234 0.412 22.485 9.565 134.435 59.983 305.314 76.238 761.997 161.823 1859.903 1562.67 30.83 1531.84 0.02 0.15 56.82 WS05-28 0.003 18.423 0.075 1.262 3.754 0.691 25.768 9.865 134.315 59.939 296.515 71.285 712.008 147.629 1821.177 1481.53 24.21 1457.32 0.02 0.21 300.82 WS05-29 0.004 35.127 0.083 1.768 4.805 0.560 36.981 14.534 195.832 83.381 406.337 94.943 902.927 182.187 2596.732 1959.47 42.35 1917.12 0.02 0.13 476.84 WS05-30 0.036 28.599 0.176 3.424 7.606 1.394 51.304 19.131 240.823 97.181 453.263 101.128 968.755 193.054 2897.227 2165.87 41.24 2124.64 0.02 0.22 88.05 WS02-1 0.012 34.124 0.201 3.717 7.501 2.472 33.922 10.145 110.736 40.545 175.905 38.370 354.954 72.500 1190.890 885.10 48.03 837.08 0.06 0.47 171.62 WS02-2 0.004 47.559 0.028 0.832 1.807 0.754 11.337 3.437 45.540 19.866 103.023 26.165 283.910 69.933 671.635 614.20 50.98 563.21 0.09 0.51 1098.02 WS02-3 0.036 38.471 0.057 1.129 1.884 0.852 13.736 4.517 57.026 24.387 123.912 31.368 334.975 77.953 794.007 710.30 42.43 667.87 0.06 0.51 208.54 WS02-4 0.012 50.641 0.028 0.917 2.720 1.204 23.208 8.413 108.997 44.986 213.779 49.899 493.407 105.741 1389.597 1103.95 55.52 1048.43 0.05 0.46 663.38 WS02-5 0.028 25.975 0.035 0.491 1.696 0.609 9.999 3.803 50.945 22.719 116.668 30.012 320.913 76.685 716.429 660.58 28.83 631.74 0.05 0.45 204.19 WS02-6 0.002 39.230 0.043 1.074 1.639 0.847 14.867 5.382 65.972 26.461 127.859 29.241 297.651 61.893 825.531 672.16 42.83 629.32 0.07 0.52 1165.23 WS02-8 0.022 49.184 0.100 1.682 4.625 1.492 25.052 8.713 107.265 41.207 186.206 42.565 411.247 85.181 1270.296 964.54 57.11 907.44 0.06 0.42 255.34 WS02-10 0.037 39.545 0.062 0.682 1.360 0.751 9.690 3.256 44.980 21.913 123.529 33.255 385.436 97.691 775.348 762.19 42.44 719.75 0.06 0.63 201.55 WS02-11 0.021 50.670 0.048 0.923 3.155 1.071 21.971 7.807 103.572 42.221 202.132 45.845 453.713 95.438 1281.416 1028.59 55.89 972.70 0.06 0.39 393.96 WS02-12 0.058 79.046 0.052 1.273 3.551 1.560 23.297 8.214 102.291 40.931 194.555 45.875 471.126 105.613 1292.794 1077.44 85.54 991.90 0.09 0.52 351.83 WS02-13 0.007 41.369 0.031 0.585 1.481 0.882 10.855 3.720 45.719 19.385 103.144 24.923 266.428 61.299 660.738 579.83 44.36 535.47 0.08 0.67 678.70 WS02-14 0.090 42.582 0.057 0.907 2.388 0.960 15.585 5.242 67.882 29.502 146.837 35.601 377.324 83.402 952.952 808.36 46.98 761.37 0.06 0.48 145.43 WS02-15 0.001 36.232 0.025 0.652 1.487 0.687 10.554 3.614 47.289 21.155 108.615 27.361 292.008 67.054 706.786 616.73 39.08 577.65 0.07 0.53 1613.59 WS02-16 0.006 34.544 0.034 0.576 1.889 0.791 11.415 3.799 49.643 20.958 111.258 28.462 308.290 73.409 720.434 645.07 37.84 607.23 0.06 0.52 592.69 WS02-17 0.019 55.315 0.094 1.178 3.093 1.401 22.447 8.198 105.758 43.429 211.144 49.744 502.611 105.706 1372.515 1110.14 61.10 1049.04 0.06 0.51 317.77 WS02-18 0.114 33.968 0.085 0.792 2.304 0.919 14.432 5.286 72.123 29.318 141.600 33.361 341.146 71.884 906.553 747.33 38.18 709.15 0.05 0.49 84.73 WS02-21 3.329 70.750 0.675 4.084 2.962 1.097 16.614 5.693 71.338 29.382 145.671 35.768 374.958 86.700 942.341 849.02 82.90 766.12 0.11 0.48 11.57 WS02-22 0.016 34.745 0.029 0.489 1.662 0.649 11.137 3.800 52.177 22.416 116.877 28.201 305.484 70.054 710.722 647.73 37.59 610.14 0.06 0.46 403.25 WS02-23 0.107 62.564 0.076 1.118 2.358 1.186 17.166 6.850 88.307 38.545 193.851 47.299 498.511 118.403 1243.373 1076.34 67.41 1008.93 0.07 0.57 170.98 WS02-24 2.004 48.432 0.640 3.362 2.621 0.843 14.286 5.148 70.194 31.348 160.890 41.314 434.070 97.581 1022.773 912.73 57.90 854.83 0.07 0.42 10.48 WS02-26 0.005 46.151 0.095 1.871 5.035 1.709 25.118 7.616 91.112 34.882 155.620 35.799 330.432 66.691 1025.318 802.14 54.87 747.27 0.07 0.46 517.34 WS02-27 2.028 56.031 0.752 4.134 4.097 1.387 22.082 7.776 94.715 39.040 181.422 42.463 422.544 89.574 1187.650 968.05 68.43 899.62 0.08 0.45 11.12 WS02-28 0.008 47.547 0.023 0.658 2.307 0.831 14.808 5.122 69.094 31.174 158.314 38.944 424.423 95.861 1005.799 889.11 51.37 837.74 0.06 0.43 873.10 WS02-29 0.032 49.428 0.052 0.873 2.233 1.023 17.366 6.285 84.980 36.660 184.098 44.561 457.590 101.390 1191.673 986.57 53.64 932.93 0.06 0.50 297.46 WS02-30 0.004 59.507 0.064 0.916 2.714 1.230 17.426 6.273 80.858 35.278 178.230 44.319 468.570 107.968 1157.665 1003.36 64.43 938.92 0.07 0.55 961.76 表 3 乌努格吐山岩体LA-ICP-MS锆石Lu-Hf同位素分析结果
Table 3. LA-ICP-MS Zircon Lu-Hf isotopic analysis of Wunugetushan rocks
样品编号 年龄(Ma) 176Yb/177Hf 176Lu/177Hf 176Hf/177Hf εHf(0) εHf(t) TDM (Ma) TDMC(Ma) fLu/Hf WS02-001 183.79 0.035646 0.001292 0.282829 2.0 5.9 604 850 -0.96 WS02-002 181.72 0.022735 0.000914 0.282783 0.4 4.3 663 952 -0.97 WS02-003 178.76 0.023283 0.000875 0.282837 2.3 6.1 587 833 -0.97 WS02-004 177.72 0.024778 0.000996 0.282818 1.6 5.4 616 878 -0.97 WS02-005 177.38 0.030802 0.001225 0.282803 1.1 4.8 641 914 -0.96 WS02-006 178.25 0.022562 0.000964 0.282825 1.9 5.7 604 860 -0.97 WS02-007 179.62 0.020253 0.000831 0.282831 2.1 5.9 595 846 -0.97 WS02-008 177.79 0.026337 0.001096 0.282842 2.5 6.3 582 822 -0.97 WS02-009 182.76 0.022090 0.000917 0.282804 1.1 5.0 634 905 -0.97 WS02-010 182.18 0.026716 0.000988 0.282850 2.8 6.6 570 802 -0.97 WS02-011 182.91 0.023562 0.000917 0.282834 2.2 6.1 591 837 -0.97 WS02-012 177.89 0.020042 0.000854 0.282819 1.7 5.5 611 873 -0.97 WS02-013 178.39 0.026401 0.001009 0.282829 2.0 5.8 599 851 -0.97 WS02-014 178.24 0.024919 0.000902 0.282803 1.1 4.9 634 909 -0.97 WS02-015 178.58 0.027675 0.001052 0.282809 1.3 5.1 629 897 -0.97 WS02-016 177.25 0.025114 0.001094 0.282813 1.5 5.2 623 888 -0.97 WS05-001 197.97 0.067606 0.002426 0.282738 -1.2 2.8 756 1057 -0.93 WS05-002 197.19 0.060028 0.002184 0.282694 -2.8 1.3 816 1155 -0.93 WS05-003 201.82 0.073935 0.002745 0.282820 1.7 5.8 643 874 -0.92 WS05-004 202.61 0.059110 0.002155 0.282728 -1.5 2.6 765 1074 -0.94 WS05-005 197.62 0.067911 0.002509 0.282731 -1.4 2.6 768 1073 -0.92 WS05-006 201.01 0.052678 0.002027 0.282712 -2.1 2.0 786 1110 -0.94 WS05-007 203.37 0.046370 0.001688 0.282703 -2.4 1.8 792 1127 -0.95 WS05-008 199.5 0.099606 0.003588 0.282743 -1.0 2.9 775 1055 -0.89 WS05-009 201.56 0.047960 0.001782 0.282714 -2.0 2.1 778 1103 -0.95 WS05-010 202.88 0.058686 0.002184 0.282702 -2.5 1.7 805 1135 -0.93 WS05-011 202.01 0.059888 0.002143 0.282712 -2.1 2.0 789 1111 -0.94 WS05-012 203.3 0.077946 0.002817 0.282659 -4.0 0.1 882 1235 -0.92 WS05-013 200.15 0.056164 0.002059 0.282711 -2.1 2.0 788 1113 -0.94 WS05-014 202.72 0.085910 0.003052 0.282701 -2.5 1.5 825 1143 -0.91 WS05-015 198.65 0.091676 0.003159 0.282751 -0.7 3.2 753 1034 -0.90 注:εHf(t)=10000×{[(176Hf/177Hf)S-(176Lu/177Hf)S×(eλt-1)]/[(176Hf/177Hf)CHUR,0-(176Lu/177Hf)CHUR×(eλt-1)]-1};
TDM=1/λ×ln{1 +[(176Hf/177Hf)S-(176Hf/177Hf)DM]/[(176Hf/177Hf)S-(176Hf/177Hf)DM]};
TDMC=TDM-(TDM-t)×[(fcc-fs)/(fcc-fDM)],fLu/Hf=(176Lu/177Hf)S/(176Lu/177Hf)CHUR-1。
其中:λ=1.867×10-11/a[41];(176Lu/177Hf)S和(176Hf/177Hf)S为样品测量值;(176Lu/177Hf)CHUR=0.0332,(176Hf/177Hf)CHUR,0=0.282772[26];(176Lu/177Hf)DM=0.0384,(176Hf/177Hf)DM=0.28325[27];(176Lu/177Hf)平均地壳=0.015;fcc=[(176Lu/177Hf)平均地壳/(176Lu/177Hf)CHUR]-1;fs= fLu/Hf;fDM=[(176Lu/177Hf)DM/(176Lu/177Hf)CHUR]-1;t为锆石结晶年龄。 -
[1] Kirkham R V, Sinclair W D. Porphyry copper, gold, molybdenum, tungsten, tin and siliver. Geology of Canadian mineral deposit type[J]. Geology Nation America 1995(1): 421-446.
[2] Richards J P. Tectono-magmatic precursors for porphyry Cu-(Mo-Au) deposit formation[J]. Economic Geology, 2003, 98: 1515-1533. doi: 10.2113/gsecongeo.98.8.1515
[3] 侯增谦, 潘小菲, 杨志明, 等. 初论大陆环境斑岩铜矿[J]. 现代地质, 2007, 21(2): 173-180. https://www.cnki.com.cn/Article/CJFDTOTAL-XDDZ200702020.htm
Hou Z Q, Pan X F, Yang Z M, et al. Porphyry Cu-(Mo-Au) deposits no related to oceanic-slab subduction: Examples from Chinese porphyry deposits in continental settings[J]. Geoscience, 2007, 21(2): 173-180. https://www.cnki.com.cn/Article/CJFDTOTAL-XDDZ200702020.htm
[4] 侯增谦. 斑岩Cu-Mo-Au矿床: 新认识与新进展[J]. 地学前缘, 2004, 11(1): 131-143. doi: 10.3321/j.issn:1005-2321.2004.01.010
Hou Z Q. Porphyry Cu-Mo-Au deposits: Some new insights and advances[J]. Earth Science Frontiers, 2004, 11(1): 131-143. doi: 10.3321/j.issn:1005-2321.2004.01.010
[5] 芮宗瑶, 张洪涛, 陈仁义, 等. 斑岩铜矿研究中若干问题探讨[J]. 矿床地质, 2006, 25(4): 491-505. doi: 10.3969/j.issn.0258-7106.2006.04.014
Rui Z Y, Zhang H T, Chen R Y, et al. An approach to some problems of porphyry copper deposits[J]. Mineral Deposits, 2006, 25(4): 491-505. doi: 10.3969/j.issn.0258-7106.2006.04.014
[6] Oyarzun R, Ma'rquez A, Liho J, et al. Giant versus small porphyry copper deposits of Cenozoic age in northern Chile: Adakitic versus normal calc-alialine magmatism[J]. Mineralium Deposita, 2001, 36: 794-798. doi: 10.1007/s001260100205
[7] Hou Z Q, Gao Y F, Qu X M, et al. Origin of adakitic intrusive generated during Mid-Miocene east-west extension in southern Tibet[J]. Earth and Planetary Science Letters, 2004, 220: 139-155. doi: 10.1016/S0012-821X(04)00007-X
[8] Core D P, Kesler S E, Essene E J. Unusually Cu-rich magmas associated with giant porphyry copper deposits: Evidence from Bingham, Utah[J]. Geology, 2006, 34: 41-44.
[9] Harris A C, Kamenetsky V S, White N C, et al. Melt inclusions in veins: Linking magmas and porphyry Cu deposits[J]. Science, 2003, 302: 2109-2111. doi: 10.1126/science.1089927
[10] 黄蕾蕾. 内蒙古乌努格吐山矿山高精度三维地质建模与评价[D]. 北京: 中国地质大学(北京), 2020: 1-120.
Huang L L. High-precision three-dimensional geological modeling and evaluation of Unugtuishan mine in Inner Mongolia[D]. Beijing: China University of Geosciences (Beijing), 2020: 1-120.
[11] 秦克章, 李慧民, 李伟实, 等. 内蒙古乌努格吐山斑岩铜钼矿床的成岩、成矿时代[J]. 地质论评, 1999, 45(2): 180-185. doi: 10.3321/j.issn:0371-5736.1999.02.011
Qin K Z, Li H M, Li W S, et al. Intrusion and mineralization ages of the Wunugetushan porphyry Cu-Mo deposit, Inner Mongolia, northwestern China[J]. Geological Review, 1999, 45(2): 180-185. doi: 10.3321/j.issn:0371-5736.1999.02.011
[12] 秦克章, 田中亮吏, 李伟实, 等. 满洲里地区印支期花岗岩Rb-Sr等时线年代学证据[J]. 岩石矿物学杂志, 1998, 17(3): 235-240. https://www.cnki.com.cn/Article/CJFDTOTAL-YSKW803.004.htm
Qin K Z, Tian Z L L, Li W S, et al. The discovery of Indo-Sinian granites in Manzhouli area: Evidence from Rb-Sr isochrons[J]. Acta Petrologica et Mineralogica, 1998, 17(3): 235-240. https://www.cnki.com.cn/Article/CJFDTOTAL-YSKW803.004.htm
[13] 李诺, 陈衍景, 赖勇, 等. 内蒙古乌努格吐山斑岩铜钼矿床流体包裹体研究[J]. 岩石学报, 2007, 23(9): 2177-2188. doi: 10.3969/j.issn.1000-0569.2007.09.016
Li N, Chen Y J, Lai Y, et al. Fluid inclusion study of the Wunugetushan porphyry Cu-Mo deposit, Inner Mongolia[J]. Acta Petrologica Sinica, 2007, 23(9): 2177-2188. doi: 10.3969/j.issn.1000-0569.2007.09.016
[14] 谭刚. 内蒙古乌努格吐山斑岩铜钼矿床成矿作用研究[D]. 北京: 中国地质科学院, 2011: 36-63.
Tan G. Study on mineralization of Unugtuishan porphyry Cu-Mo deposit, Inner Mongolia[D]. Beijing: Chinese Academy of Geological Sciences, 2011: 36-63.
[15] 王天豪, 张书义, 孙德有, 等. 满洲里南部中生代花岗岩的锆石U-Pb年龄及Hf同位素特征[J]. 世界地质, 2014, 33(1): 26-38. doi: 10.3969/j.issn.1004-5589.2014.01.003
Wang T H, Zhang S Y, Sun D Y, et al. Zircon U-Pb ages and Hf isotopic characteristics of Mesozoic granitoids from southern Manzhouli, Inner Mongolia[J]. Global Geology, 2014, 33(1): 26-38. doi: 10.3969/j.issn.1004-5589.2014.01.003
[16] Wang Y H, Zhao C B, Zhang F F, et al. SIMS zircon U-Pb and molybdenite Re-Os geochronology, Hf isotope, and whole-rock geochemistry of the Wunugetushan porphyry Cu-Mo deposit and granitoids in NE China and their geological significance[J]. Gondwana Research, 2015, 28, 1228-1245. doi: 10.1016/j.gr.2014.10.001
[17] Zhang F F, Wang Y H, Liu J J, et al. Origin of the Wunugetushan porphyry Cu-Mo deposit, Inner Mongolia, NE China: Constraints from geology, geochronology, geochemistry, and isotopic compositions[J]. Journal of Asian Earth Sciences, 2016, 117: 208-224. doi: 10.1016/j.jseaes.2015.12.018
[18] Mi K F, Liu Z J, Liu R B, et al. U-Pb zircon, geochem-ical and Sr-Nd-Hf isotopic constraints on age and origin of the intrusions from Wunugetushan porphyry deposit, northeast China: Implication for Triassic—Jurassic Cu-Mo mineralization in Mongolia—Erguna metallogenic belt[J]. International Geology Review, 2017, 60(4): 496-512.
[19] 宓奎峰, 吕志成, 柳振江, 等. 内蒙古乌努格吐山铜钼矿床Cu, Mo同位素组成及绢云母Ar-Ar测年对区域成矿作用的启示[J]. 岩石学报, 2021, 37(6): 1875-1898. https://www.cnki.com.cn/Article/CJFDTOTAL-YSXB202106009.htm
Fu K F, Lyu Z C, Liu Z J, et al. Compositions of Cu and Mo isotopes, sericite Ar-Ar ages of Wunugetushan Cu-Mo deposit in Inner Mongolia: Implications for regional mineralization[J]. Acta Petrologica Sinica, 2021, 37(6): 1875-1898. https://www.cnki.com.cn/Article/CJFDTOTAL-YSXB202106009.htm
[20] 陈殿芬, 艾永德, 李荫清. 乌努格吐山斑岩铜钼矿床中金属矿物的特征[J]. 岩石矿物学杂志, 1996, 15(4): 346-354.
Chen D F, Ai Y D, Li Y Q. Characteristics of metallic minerals from the Wunugetushan porphyry copper-molybdenum deposit[J]. Acta Petrologica et Mineralogica, 1996, 15(4): 346-354.
[21] 李诺, 孙亚莉, 李晶, 等. 内蒙古乌努格吐山斑岩铜钼矿辉钼矿铼锇等时线年龄及其成矿地球动力学背景[J]. 岩石学报, 2007, 23(11): 2881-2888. doi: 10.3969/j.issn.1000-0569.2007.11.018
Li N, Sun Y L, Li J, et al. Molybdenite Re/Os isochron age of the Wunugetushan porphyry Cu/Mo deposit, Inner Mongolia and its implication for metallogenic geodynamics[J]. Acta Petrologica Sinica, 2007, 23(11): 2881-2888. doi: 10.3969/j.issn.1000-0569.2007.11.018
[22] He X L, Yu Q Y, Liu S Y, et al. Origin of the Erdaohe Ag-Pb-Zn deposit, central Great Xing'an Range, northeast China: Constraints from fluid inclusions, zircon U-Pb geochronology, and stable isotopes[J]. Ore Geology Reviews, 2021, 107: 104309.
[23] Sláma J, Košler J, Condon D J, et al. Plešovice zircon—A new natural reference material for U-Pb and Hf isotopic microanalysis[J]. Chemical Geology, 2008, 249(1-2): 1-35. doi: 10.1016/j.chemgeo.2007.11.005
[24] AndersenT. Correction of common lead in U-Pb analyses that do not report 204Pb[J]. Chemical Geology, 2002, 192(1-2): 59-79. doi: 10.1016/S0009-2541(02)00195-X
[25] LiuY S, Hu Z C, Zong K Q, et al. Reappraisement and refinement of zircon U-Pb isotope and trace element analyses by LA-ICP-MS[J]. Chinese Science Bulletin, 2010, 55: 1535-1546. doi: 10.1007/s11434-010-3052-4
[26] Goolaerts A, Mattielli N, Jong J D, et al. Hf and Lu iso-topic reference values for the zircon standard 91500 by MC-ICP-MS[J]. Chemical Geology, 2004, 206(1-2): 1-9. doi: 10.1016/j.chemgeo.2004.01.008
[27] Griffin W L, Pearson N J, Belousova E, et al. The Hf isotope composition of cratonic mantle: LAM-MC-ICPMS analysis of zircon megacrysts in kimberlites[J]. Geochim Cosmochim Acta, 2000, 64: 133-147. doi: 10.1016/S0016-7037(99)00343-9
[28] Griffin, W L, Wang X, Jackson S E, et al. Zircon geochemistry and magma mixing, SE China: Insita analysis of Hf isotopes, Tonglu and Pingtan igneous complexes[J]. Lithos, 2002, 61: 237-269. doi: 10.1016/S0024-4937(02)00082-8
[29] Rubatto D, Gebauer D. Use of cathodoluminescence for U-Pb zircon dating by IOM Microprobe: Some examples form the western Alps[M]//Cathodoluminescence in Geoscience. Germany: Springer-Verlag Berlin Heidelberg, 2000: 373-400.
[30] Cleasson S, Vetrin V, Bayanova T, et al. U-Pb zircon ages from a Devonian carbonatite dyke, Kola peninsula, Russia: A record of geological evolution from the Archaean to the Palaeozoic[J]. Lithos, 2000, 51: 95-108. doi: 10.1016/S0024-4937(99)00076-6
[31] Belousova E A, Griffin W L, O' Reilly S Y, et al. Igneous zircon: Trace element composition as an indicator of source rock type[J]. Contributions to Mineralogy and Petrology, 2002, 143 (5): 602-622. doi: 10.1007/s00410-002-0364-7
[32] Griffin W L, Belousova E A, Shee S R. Crustal Evolution in the northern Yilarn Craton: U-Pb and Hf-isotope evidence from detrital zircons[J]. Precambrian Research, 2004, 131(3-4): 213-282. doi: 10.1016/j.precamres.2003.12.010
[33] Hoskin P W O, Kinny P D, Whborn D, et al. Indentifying accessory mineral saturation during differentiation in granitoid magmas: An integrated approach[J]. Journal of Petrology, 2000, 41(9): 1365-1396. doi: 10.1093/petrology/41.9.1365
[34] Rubatto D. Zircon trace element geochemistry: Partitioning with garnet and the link between U-Pb ages and metamorphism[J]. Chemical Geology, 2002, 184(1-2): 123-138. doi: 10.1016/S0009-2541(01)00355-2
[35] Hoskin P W O, Ireland T R. Rare earth element chemistry of zircon and its use as a provenance indicatior[J]. Geology, 2000, 28(7): 627-630. doi: 10.1130/0091-7613(2000)28<627:REECOZ>2.0.CO;2
[36] Hoskin P W P. Trace-element composition of hydrothermal zircon and the alteration of hadean zircon from the Jack Hills, Australia[M]. Geochimica et Cosmochimica Acta, 2005, 69(3): 637-648. doi: 10.1016/j.gca.2004.07.006
[37] 吴福元, 李献华, 郑永飞, 等. Lu-Hf同位素体系及其岩石学应用[J]. 岩石学报, 2007, 02: 185-220. https://www.cnki.com.cn/Article/CJFDTOTAL-YSXB200702002.htm
Wu F Y, Li X H, Zheng Y F, et al. Lu-Hf isotopic systematics and their applications in petrology[J]. Acta Petrologic Sinica, 2007, 23(2): 185-220. https://www.cnki.com.cn/Article/CJFDTOTAL-YSXB200702002.htm
[38] Sun S S, Mcdonough W F. Chemical and isotopic systematics of ocean basalts: Impications for mantle composition and processes[M]. London: Geological Society of London and Blackwell Scientific Publications, 1989: 313-345.
[39] Cherniak D J, Watson E B. Pb diffusion in zircon[J]. Chemical Geology, 2000, 172: 5-24.
[40] 吴元保, 郑永飞. 锆石成因矿物学研究及其对U-Pb年龄解释的制约[J]. 科学通报, 2004, 49(16): 1589-1604. https://www.cnki.com.cn/Article/CJFDTOTAL-KXTB200416001.htm
Wu Y B, Zheng Y F. Zircon genetic mineralogy and its constraints on the interpretation of U-Pb age[J]. Chinese Science Bulletin, 2004, 49(16): 1589-1604. https://www.cnki.com.cn/Article/CJFDTOTAL-KXTB200416001.htm
[41] Söderlund U, Patchett P J, Vervoort J D, et al. The 176Lu decay constant determined by Lu-Hf and U-Pb isotope systematic of Precambrian mafic intrusions[J]. Earth and Planetary Science Letters, 2004, 219: 311-324. doi: 10.1016/S0012-821X(04)00012-3